Nonfoaming compositions and methods of making same



Patented Feb. 3, 1948' NONFOAMING COMPOSITIONS AND METH! ODS OF MAKING SAME Garland n. B. Davis, Hillside, and John 0. Zimmer, Union, N. J., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing.

The present invention relates to spumiferous compositions of matter containing foam-depressing or foam-preventing agents and to improved methods for making such compositions, and, more particularly, the invention is con cerned with lubricating oils, greases and other compounded lubricants, metal salts of the petroleum oil sulfonic acids, and additives for lubricating compositions, and also with superior methods for making such sulfcnates, greases and additives for lubricating compositions.

The formation of foam is distinctly disadvantageous under many circumstances, as, for example, in engine oils for internal combustion engines, particularly the heavy duty type of oils. Many internal combustion engines employ both pressure and splash systems of lubrication, whereas other motors use only one of the systems. In either case the formation of foam on top of the 011 during the operation of the motor leads to serious consequences due to lack of lubrication. This is particularly so in pressure lubricating systems employing the so-called dry sump" operation where the oil returning from the engine parts is picked up by a scavenging pump and returned to the lubricant reservoir. Since the scavenging pump normally has a capacity of several times the volume of the oil returning from the engine, a large amount of air is pumped along with the lubricant and as a result foam tends to build up inthe oil reservoir to a point where some oil may be-lost through the breather pipe or to a point where the pres sure pump delivers foam instead of oil to the various moving parts of the engine, with a resultant Serial No. 516,188 16 Claims. (01. 252-318) Application December so, 1943,

extent that the oil level will fall below the gear train. These oils usually owe their ability to withstand high unit loads to the presence of additives containing sulfur, chlorine or phosphorus or to the presence of lead soaps. Hydraulic and shock absorber oils likewise need protection against foaming.

Another instance where a serious foaming problem exists is in the production of metal sulfonates from petroleum oil sulfonic acids, and particularly the preferentially oil-soluble sulfonic acids. In general the petroleum oil sulfonic acids are produced when mineral oil or a fraction thereof is treated with concentrated sulfuric acid. The oil-soluble sulfonic acids are recovered as metal sulfonates by first removing the acid sludge, converting the sulfonic acids to sulfonates by neutralization with alkali and removous solution of mineral salts.

ing the resulting metal sulfonates from the oil by washing the oil with aqueous alcohol. The alcohol is then recovered by distillation, leaving as a residue metal sulfonates mixed with an aque- Near the end of the alcohol distillation step large volumes of foam are produced and space in the apparatus must be provided for accommodating this foam so as to prevent it going over into the condenser.

There are many uses for sulfonates which require a metal sulfonate other than an alkali metal sulfonate. These metal sulfonates, as for example the alkaline earth metal sulfonates, are

- made by a process of double decomposition belack of lubrication. Many heavy duty lubricat- I ing oils for gasoline and Diesel engines contain dissolved therein from 0.55% of various metalloorganic additives, such as metal phenates, phenol sulfides, carboxylates, sulfonates, alcoholates, metal salts of esters of phosphorus and thin phosphorus acids, etc., which as oil soluble detergents act to maintain bearings and the internal surfaces of the engines free of gummy or varnish like deposits. Oils containing additives of the above type are especially prone to foam under many conditions. The addition to oils of certain non-metallic agents, such as phosphatides, organic esters, fatty compounds,thickeners, etc., also promotes foaming on occasion.

In the case of gear lubricants, such as those designed for the lubrication of automobile rear ends and transmissions, whensuch lubricants showa marked tendency to form foam durin use the foam entraps the lubricant to such an tween alkali metal sulfonates and an aqueous solution of an alkaline earth metal salt. After the reaction is completed the material is concentrated by boilingoif the water. foaming occurs which at times reaches such proportions as to require an evaporator 10 times as large in volume as the volume of the metal sulfonates being concentrated. Another'process which is conducive to the formation of foam is that of making greases such as ordinary cup grease. The ordinary procedure for making greases is to melt soap stock in lubricating oil and then react the soap stock with an alkali or alkaline material added in the form of an aqueous solution or suspension after which most, if not all, or the water is boiled off. During the boiling ofi of the water the hot grease is usually stirred vigorously and large quantities of foam are produced. Still another instance in which the presence of foam attains troublesome amounts is in the production of additives for lubricating compositions. For example, in the production of metal phenates and phenol sul- Here again fides in oil solution. large volumes of foam are produced during the neutralization step in which the water of reaction must be drivenoif. It has been found that in processes where foaming occurs, vessels at least 2 and 3 times and often 10 times the size, measured by volume of the material being processed, must be provided in order to secure expeditious results. It is therefore apparent that if foaming could be eliminated in these various processes, appreciable economies in time. labor and materials could be eifected.

The principal object of the present invention is to provide lubricating compositions which will not froth or foam during user Another object is to dispense with the troublesome foaming accompanying ebullition in the dehydration of the oil solutions and mixtures. These and other objects will be apparent to those skilled in the art upon reading the following description.

It has now been found that certain highly fluorinated organic compounds of the aliphatic, aromatic, naphthene and cyclo aliphatic hydrocarbon type in which the major proportion of the hydrogen has been replaced with fluorine, will, when added to spumiferous compositions, reduce to negligible proportions the tendency of such compositions to form foam when stripped by means of heat and will also when present in small amounts materially depress foaming due to aeration or deaeration in oleaginous compositions of matter, such as engine oils (both'compounded and uncompounded), hydraulic fluids, shock absorber oils, cutting oils, extreme pressure lubricants, process oils, saturating compositions, asphaltic oils and various other related compositions, as well as oil concentrates containing from 5-50% or more of additives for use in preparing the above products. The fluorinated hydrocarbons may be added to the oleaginous compositions at any stage of their manufacture or may be incorporated with one or more .of this additive prior to the addition of the additive or mixture of additives to the oily material as for instance the fluorinated hydrocarbon may be included with the metal soaps of the petroleum oil sulfonic acids, such as the calcium soaps; the metal soaps of organic thiophosphoric acid, such as the zinc soaps; metal phenates, metal alkylated phenates, metal phenol sulfides, metal alkylated phenol sulfides, like metal tertiary octyl phenol sulfide and metal alkylated phenol sulfides reacted with P2S5, where the metal is a polyvalent metal such as barium; and the like. The fluorinated compounds are conveniently incorporated in such additives, prior to the addition of the latter to the oily material, in amounts from 0.001% to by weight. The fluorinated compounds may also contain chlorine, bromine, or iodine, oxygen, nitrogen, phosphorus, sulfur or metal derivatives of functional groups in the molecule.

The highly fluorinated compounds contemplated within the scope of the present invention are known and their properties and preparation have been described by both Bochemiiller 1 and Simons. For the purpose of the present invention it is preferred to use those highly miiller, Annalen, 506, 20 (1933) 3 Simons and Block. J. Am.

Ibld., 61: 2962 (1939);

Ibid., 62: 3477 (1940).

Chem. Soc, 59: 1407 (1937) Simone, Bond and MacArthur,

fluorinated compounds which have boiling points above 85 C. at atmospheric pressure and viscosities between 30-2000 fS. ULIS.' at 210rF. This range includes those highly fluorinated compounds having from 5-50 carbon atoms to the molecule, such as heptafluoropentane (C5H5F1), octafluoropentane (CsHaFa) dodecafluoropentane (CsFiz) and similar derivatives of such hydrocarbons as pentadecane, eicosane, and cyclic, isomeric, and normal aliphatics of 5 to 50 carbon atoms, in which at least half of the hydrogen atoms are replaced by fluorine atoms. Also, these fluorinated compounds may be.produced from hydrocarbons from various sources including petroleum fractions ranging from gasoline to heavy lubricating oils, or waxes and petrolatums. These fluorinated hydrocarbons will contain from about 60 to about fluorine, from about 20 to about 37% carbon and from zero to about 3% hydrogen. It is preferred to use fluorinated compounds in which substantially all of the hydrogen has been replaced by fluorine. The particular method by which these fluorinated compounds may be prepared forms no part of the present invention but it may be stated that these highly fluorinated materials are preferably produced by the catalytic fluorination of hydrocarbons as is well known in the art. The materials described above are quite insoluble in mineral lubricating oil and, therefore, possess the desired foam suppressing properties.

In practicing the present invention as applied to the dehydration of. spumiferous compositions the fluoro-organic compounds may be added to the spumiferous composition to be dehydrated either before or after the composition has been charged to an evaporating vessel, in an amount equivalent to from 1-50 grams per thousand square inches of evaporating surface. Since many evaporation vessels have or provide irregular evaporating surfaces, the amount of fluoro-organic compound added to the spumiferous compositions can be calculated on the basis of weight per cent of the charge to the evaporator. Expressed in this manner it requires from 0.0001-10% by weight (based on the total charge) to suppress the formation of foam during subsequent evaporation in order that the dehydration can be conducted rapidly without interference from foam. Such processes can be run either by a batch method or continuously. When it is desired to suppress foaming in compositions such as lubricants, hydraulic media, and the like the fiuoro-organic compound is added to such compositions in an amount from .0001-10% by weight. The fluoro-organic compounds are substantially insoluble, and although having a greater specific gravity than many common fluids, it is believed that the fluorine compounds possess the characteristic of concentrating at the interface between the liquid phase and the gaseous foam phase, thereby breaking or destroying any foam bubbles present or as formed. The choice of fluorine compound will be controlled somewhat by operating conditions, particularly by temperature. Since the highly fluorinated compounds show a very marked change in viscosity per degree change in temperature, it is advisable to select. a fluorinated compound which will be liquid but substantially non-volatile at the given temperature of operation.

The following examples are given merely for the purpose of illustrating the principles of the present invention.

Example 1 fiuorinated hydrocarbon containing 26.30% carbon, 0.09% hydrogen and 71.30% of fluorine and having a, viscosity of 67 S. U. S. at 210 F. is employed, it is possible to complete the heating operation' in the time and to use a 600 ml. beaker.

Emample 2 816 pounds of 30% sulfonate in oil and 629 pounds of an 11% calcium chloride solution in water and 1 pound of a highly fluorinated hydrocarbon containing 26.30% carbon, .09% hydrogen and 71.30% of fluorine and having a viscosity of 67 S. U. S. at 210 F. are placed in a kettle and heated to 240 F. for 1% hours to react the sodium sulfonate with the calcium chloride and to drive off the water by evaporation. Without the fluorine compound only about 325 pounds of reactants can be charged to the kettle and it would require about 12 hours to complete the reaction and drive off all the water.

Example 3 600 grams of a commercial S. A. E. 30 heavy duty mineral lubricating oil (containing detergent-type additives) were heated to 100 F. and agitated for 10 minutes with a beater rotating at the rate of 1000 R. P. M. The volume of the oil increased 22% as a result of the high speed agitation, The volume change of the oil due to dispersion of air into the oil was taken as a measure of the foaming tendency of the oil. Various highly fiuorinated hydrocarbons were then tested for defoaming characteristics with the following result:

, Percentvolume increase S. E. 30 heavy duty motor oil 22 S. E. 30 heavy duty motor oil+0.1% 9 S, E. 30 heavy duty motor oil+0.1% S. E. 30 heavy duty motor oil+0.01% S E. 30 heavy duty motor oil+0.1% E. 30 heavy duty motor oil+0.01%

E. 30 heavy duty motor oil+0.1%

A A A OQOONO A highly fluorinated aliphatic hydrocarbon containing 26.30% carbon, .09% hydrogen and 73.30% of fluorine and having a viscosity of 67 S. U. S. at 210 F.

A highly fluorinated aliphatic hydrocarbon containing 24.24% carbon. 0.12% hydrogen and*67.03% fluorine.

A highly fluorinuted aliphatic hydrocarbon containing 24.25% carbon, 0.05% hydrogen, 73.59% fluorine.

A highly fluorinuted aliphatic hydrocarbon containing 24.66% carbon, 0.18% hydrogen and 68.07% fluorine.

It will be understood that other and various examples are covered by this invention, such as a. composition consisting essentially of a metal salt of petroleumsulfonic acid, for example calcium petroleum sulfonate, containing from .001 to 10% by weight of the fiuoro-organic compound or a metal salt of an alkyl henol sulfide containing .001 to 10% of the fluoro-organic compound, especially the barium salt compound and particularly the barium tertiary octyl phenol sulfide containing 0.1 to 10% by weight of the fluoroorganic material. In lieu of the barium salt per se, the reaction product of barium tertiary octyl phenol sulfide and P285 may be used. Thus a satisfactory composition may consist essentially of highly efiective in reducing the foaming tendencies or the heavy duty lubricant.

What is claimed is: v

1. A composition of matter consisting essentially of a metal sulfonate of a petroleum sulfonic acid and from .001-10% by weight of a fluoro-organic compound chosen from the group consisting of aliphatic and cyclo aliphatic fiuoroorganic compounds, having from 5-50 carbon atoms to the molecule and containing 60-80% fluorine, 20-37% carbon and 0-3% hydrogen.

2. A composition oi matter consisting essentially of a metal sulfonate of a petroleum sulfonlc acid and from .001-10% of a fluoro-organic aliphatic hydrocarbon containing about 26% carbon, about 0.1% hydrogen and about 73% of fiuorine and having a viscosity of 67 S. U. S. at 210 F.

3. A composition of matter consisting essentially of a metal sulfonate of a petroleum sulfonic acid and 0.1% of a fluoro-organic aliphatic hydrocarbon which contains ,about 26% carbon, about 0.1% hydrogen and about 73% of fluorine and which has a viscosity of 67 S. U. S. at 210.F.

4. A composition of matter consisting essentially of a calcium suifonate ot a petroleum sulfonic acid and from .001-10%. by weight of a fluoro-organic compound having from 5-50 carbon atoms to the molecule and containing 60-80% fluorine, 20-37% carbon and 0-3 hydrogen.

5. A composition of matter consisting essentially of a calcium sulfonate of a, petroleum sulfonic acid and 0.1% of a fiuoro-organic aliphatic hydrocarbon containing about 26% carbon, about 0.1% hydrogen and about 73% fluorine and which has a viscosity of 67 S. U. S. at 210 F.

6. A composition of matter consisting essentially of a metal salt or an alkyl phenol sulfide and .001-10% of a fiuoro-organic compound having from 5-50 carbon atoms to the molecule and containing 60-80% fluorine, 20-37% carbon and 0-3% hydrogen.

7. A composition of matter consisting essentially of a barium salt of an alkyl phenol sulfide and .001-10% of a. fluoro-organic compound having from 5-50 carbon atoms to the molecule and tially of a barium salt of tertiary octyl phenol sulfide and .1-10% of a fluoro-organic compound having from 5-50 carbon atoms to the molecule and containing 60-80% fluorine, 20-37% carbon and 0-3% hydrogen.

9. A composition of matter consisting essentially of a metallo-organic additive for mineral lubricating oils having a tendency to substantially increase the foaming characteristics or such oils at elevated temperatures. with which is incorporated from 0.001 to 10% by weight of a fiuoro-organic compound having 5 to 50 carbon atoms in the molecule and containing from about 60 to fluorine, from about 20 to about 37% carbon, and from 0 to about 3% hydrogen.

10. A composition of matter consisting essentially or a metallo-organic additive for mineral lubricating oils having a tendency to substantially increase the foaming characteristics of such oils from about.60 to 80% flourlne, from about 20 to about 37% carbon, and from to about 3% nydrogen, the amount of the said fluoro-organic compound being suflicient to reduce foaming in a mineral lubricating oil containing 0.5 to 5% of the said metallo-organic additive.

11. A composition of matter consisting essentially of a metal sulfonate of petroleum sulfonic acid and a fiuoro-organic compound chosen from the group consisting of aliphatic and cyclo-aliphatic fluoro-organic compounds, having from 5 to 50 carbon atoms to the molecule and containing 60 to 80% fluorine, 20 to 37% carbon and 0 to 3% hydrogen, the amount of said fluoro-organic compound being sufilcient to reduce foaming in a mineral lubricating oil containing 0.5 to 5% of the said metal sulfonate.

12. A composition of matter consisting essentially of a metal sulfonate f a etroleum sulfonic acid and a fluoro-organic aliphatic hydrocarbon containing about 26% carbon, about 0.1% hydrogen and about 73% fluorine and having a viscosity of 67 S, U. S. at 210 F., the amount of said fluoro-organic compound being suflicient to reduce foaming in a mineral lubricating oil containing 0.5 to 5% of the said metal sulfonate.

13. A composition of matter consisting essentially of a calcium sulfonate of a petroleum sulfonic acid and a fluoro-organic compound having from 5 to 50 carbon atoms to the molecule and containing 60 to 80% fluorine, 20 to 37% carbon and 0 to 3% hydrogen, the amount of said fluoro-organic compound being sufiicient to reduce foaming in a mineral lubricating oil containing 0.5 to 5% of said calcium suffonate.

14. A composition f matter consisting essentially of a metal salt of an alkyl phenol sulfide and a fluoro-organic compound having from 5 L0 tially of a barium salt 8 carbon atoms to the molecule and containing to fluorine, 20 to 37% carbon and 0 to 3% hydrogen, the amount of said fluoro-organic compound being sufilcient to reduce foaming in a mineral lubricating 011 containing 0.5 to 5% of said metal salt.

15. A composition of matter consisting essentially of a barium salt of an alkyl phenol sulfide and a fluoro-organic compound having from 5 to 50 carbon atoms to the molecule and containing 60 to 80% fluorine, 20 to 37% carbon and 0.3% hydrogen, the amount of said fluoro-organic compound being suflicient to reduce foaming in a mineral lubricating oil containing 0.5 to 5% of the said barium salt.

16. A composition of matter consisting essenof tertiary octyl phenol sulfide and a fiuoro-organic compound having from 5 to 50 carbon atoms to the molecule and containing 60 to 80% fluorine, 20 to 37% carbon and 0 to 3% hydrogen, the amount of said fiuoroorganic compound being sufiicient to reduce foaming in a mineral lubricating oil containing 0.5 to 5% of the said barium salt.

GARLAND H. B. DAVIS. JOHN C. ZIMMER.

REFERENCES CITED The following references are of-record in the file of this patent:

UNITED STATES PATENTS 

